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WOODLOT FOKESTRY 



r.V DIt. .TUDSON F. C't.AUK. lUUKAr OF FOUFSTltV. WASI 1 IX(;TOX. I). C. 



The discovcM-v of the silviculluial <'li;u"ict(»i-isti('s of oni- Anu'iican forest 
treos, toucllier willi the disscniiiuilion of this knowliMljic aiiiouu xUv own- 
ers of wooillaiKis for jfi-actical piiriioses. lias lonj:,- been the most inijioi-taut 
feature of the work of the National linreau of Forestry. Dnrinu' the last 
five years a special effort has been made to reach and solve the problems 
of the farmer. This effort has been induced because of a general lack of 
information on the part of the farmers in the management of woodlands 
and the increasing imj)ortance of the ])roduct of the woodlot. 

Few ajtpreciate the imjiortance of the farmer's woodlot in the national 
e(M)nomy. To emjdiasi/e this ])oint. I shall (piote a few statistics fiom the 
twelfth census (i!»Otri. The average farm in the I'nited States contains 
1-17 acres, of which 72 are recorded as "improved" and 74 "unimproved." 
This "nnimjiroved" area of American farms foots U}) the enormous total 
of i2<>,(i()U.0(i() acres. The unim])roved areas consist of woodlands, treeless 
swamp and barren lands. A very conservative estimate of the amount 
of unim])roved lands in the I'nited States capa1)Ie of i)roducing timber is 
30<>.<MI0.()()0 acres. A vast em])ire of actual and })otential woodlotsi The 
vaJuc of the total ])rodnct of the hunber camjis of the United States (in- 
cluding logs, bark for tanning, charcoal, rived shingles, shijts' knees, posts, 
ties and all other products of the lumber canqis) was. in ISSt). .i?174,(t(HI.- 
0(1(1. The value of the product of the woodlots of the United States (in- 
cluding "only the wood, lumber, ties, etc. which the farmers cut in con- 
nettion with their ordinary farming o]>erations,") and not including 
maple syrup or sugar, was $110, (MX), 0(10. In other words, in 1881>, the farm- 
ers' woodlots of the country produced an amount very nearly equal to 
two-thirds of the value of the product of the regular lumber industry 
as it was deliv<M'ed at the mills. 

Not only is the present jn-oduct of the woodlot of very great (Mimomic 
im]iortance, but it \\ill certainly be increasingly so as the natural sup- 
]:lies of virgin timber disapi)ear. The following statistics from the 
twelfth census illustrate the increasing imjiortance of the woodlot as de- 
velo])ment ])rogresses in the different States: 

H 1! 1 ' , ', 



48 STATE OF MICHIGAN. 



TOTAL VALUE OF PRODUCT. 

Of Lumber Cauii>s. Of Woodlots. 

Washiiioton 111,332,000 |1.002,000 

^yisconsin 18,112,000 6,116,000 

jMichioan 20,462,000 7,530,000 

Indiana 4,058,000 5,235,000 

Ohio 4,384,000 5,625,000 

New York 4,364,000 7,671,000 

Counectieiit 493.000 1,276,000 

^"N'asluuiiton represents llie newest type. Its lumber camp ])roduct ex- 
ceeds that of the woodlots in the ratio of 11 to 1. Micliigan has an inter- 
mediate position, having a proportion of about 2.8 to 1. New York has 
the bahmce turned the other Avay, and in the proportion of 1 to 1.8, and 
Connecticut, where lumbering as a business has become ver}- much re- 
duced, has the proportion of 1 to 2.6 in favor of the woodlots. 

It is only fair to add, however, that the product of the woodlot is used 
largely, though by no means wholly, in an unmanufactured or slightly 
manufactured form (cordwood, railway ties, posts, etc.), wdiile the prod- 
uct of the lumber camps is in a much larger degree the raw material for a 
vast series of manufactures. It is also worthy of note in this connection 
that the farmer is usually his own logger. This work is done at a time 
of 3-ear when there is little else to do, and in many cases the entire 
amount receiA-ed for the ]n'oduct may be regarded as clear gain to be 
credited to the woodlot. The lumberman, on the other hand, must build 
his camps, purchase his horses, camp supplies, tools, etc., and especially 
employ labor, the cost of all which must be deducted from the sale value 
of his product in determining his profit. The census returns show the 
value of the stumpage of the cut of |174,000,000 worth of product by 
the lumbermen during the cejQsus year to have been |58,177,000. It is not 
improbable that the farmers' cut of |110,000,000 represents as large a 
real stumj)age value. 

The value of the woodlot as a national asset can hardly be overesti- 
mated, and it should in future, with improved methods of management, 
ever contribute an increasing amount of material for general consump- 
tion. In several respects it has distinct advantages over the timber tract. 
Among these may be mentioned its nearness to the points of consumption, 
together with the ])racticability of an intensit}^ of management that can 
hardly be ho])ed for op the larger areas, and which is only in part offset 
by the cheapness of the wild land. 

The value of the woodlot as a source of fuel has recently been brought 
very prominently to the notice of the public generally by the realization 
that it is the only buffer that stands betAveen the people and the higher 
prices aa hich the coal combine may ask the moment they have the field to 
themselves. The people have also a fresh recollection of the fact that the 
woodlot is the only thing that stands between them and actual suffering 
by cold in the event of a coal strike. The cities and villages are more 
interested in this matter than the farmers themselves, for if a farmer has 
only a small supply of wood, he will naturally provide for the comfort 
of his OAvn family before he offers any for sale. A consideration of this 



FORESTRY COMMISSIUX. 49 

should lead the urban poimlation to heartily sn|i|M)rl a nidderalc and 
equitable tax rate for the farmers' woodlois. 

This article, however, is intended to refer especially to tiie woodlot con- 
ditions as I have found them in Michij;an. II is perhaps hardly neces- 
sary to say that these conditicuis are exceedinj^ly unsatisfactory. A very 
few farmers, indeed, have nnide any real etfort to improve this portion of 
their farms, and those who have done so have in many eases made very 
serious mistakes. Such mistakes were inevitable', for the farmers have 
not liad access to information reiiardinj;- correct methods of handlin;^- 
woodlands. The necessity itself for better metho<]s is a comparatively 
recent development. The averaj^e ^licliigan farmer of to<lay well remem- 
bers when the trees were rejiarded as the natural enemies of the tiller of 
the soil, and their removal was the farmers" j^reatest labor. The change 
in the times has come without brin*>ing the knowledge necessary to meet 
the changed conditions. It is a most unfortunate fact that knowledge o^ 
correct methods of woodland management cannot be learned experiment- 
ally by the average farmer, as is the case to a greater or less extent with 
almost all other farming operations. Time element alone makes this a 
practical impossibility — years and even decades being often required for 
a ilemonstration, instead of days or weeks. Aside from this, few, if any, 
farmers have had the recjuisite training to enable them to carry out any 
i-eally careful forestry investigation. The result has been that in the 
absence of instruction almost every etfort for improvement has been merely 
guess work,while the gTcat majority of farmers have not interested them- 
selves in the matter. 

The average Michigan farm contains about 80 acres. Of this area 58 
acres are recorded as improved and 28 acres as unimproved. It is probable 
that three acres per farm w(uild on the average be a liberal reduction 
from the unimproved land for such Avaste areas as are unsuited for tree 
growth. This leaves an area of 25 acres which is at present occupied by 
tr-ees or capable of being so occupied. This gives a woodlot area of over 
5,000,000 acres on the 210,000 farms of the State. As already suggested, 
it is sadly true that the term "unimproved" is not inaptly applied to these 
5,000,000 acres, for there is nearly or quite one-half of this area, which, 
in its present condition, is all but wholly unproductive, and on the remain- 
ing ])ortion, as already indicated, there has been but little etfort ex[)ended 
that would entitle any considerable portion to be classed as 'improved." 

The value of the woodlot product of Michigan has already been referred 
to as amounting to .i{!T,5.')0.000 in 1800 — a sum which compares favorably 
with the combined products of the orchard, grapery and small fruit gar- 
den, which in the same year totaled |5,860,000 for the State. When we 
recall that about one-half of the unimproved area of the farms is at j)resent 
all but wholly unproductive, it will be seen that the producing area has 
yielded about .f3.()0 per acre to the woodlot owners in 1899. Michigan 
enjoys the distinction of having a larger return acre for acre from her 
woodlots than any other State in the Union. Were this assuredly a bona 
fide income, it would be a matter for congratulation. That it is largely 
a result of the stripping of the land at an unusually rapid rate is evi- 
denced by the very unsatisfactory conditions for wood production ob- 
taining on the average woodlot, and by the rapidity with which the wood- 
lots are disappearing in the four southern tiers of counties. 

This view of the imi)ortance of the woodlot as a producer of future tim- 
R — B 2 



60 STATE OF MICHIGAN. 

ber supplies and as a very considerable source of income to a very large 
class of the population of the country has induced the Bureau of Forestrj- 
to offer to co-operate with farmers owning woodlands in their manage- 
ment.* On application, the bureau offers to send a trained forester to 
make a careful examination on the ground of the woodlot. It is the duty 
of the forester to point out the defects of the woodlot and their cause, 
and how thej may be most quickly and economically remedied; to mark 
sample areas, showing which trees should be removed where removal is 
desirable, and where planting is desirable or desired; to advise regarding 
the species best suited to the soil and the locality. It is also customary 
for the forester to prepare a detailed report on the conditions found, with 
notes on their treatment. A copy of this report — which usually indicates 
the management for about ten years — is afterwards sent to the farmer for 
his future guidance. This service is free to all, but the bureau reserves 
the right to accept or decline applications, as may be deemed wise, with 
due regard to the objects for which the offer is made, and the limitations 
of the funds at their disposal for this work. 

It is hoped that by this means it will eventually be possible to have in 
every county, and perhaps in every tOAvnship, at least one woodlot which 
will be handled in a correct way, and Avhich will thus serve as an object 
lesson to the farmers in its vicinity of the practicability of woodlot for- 
estry, A report on a woodlot examined by the writer in St. Joseph county 
during the spring of 1904 is given herewith, that those interested may 
have a clearer idea of the scope of the woodlot work carried on by the 
government, and that all who read may get a forester's opinion of a very 
common type of woodlot in Southern Michigan. 

♦Applications should be sent to Thomas H. Sherrard, Chief of Division of Forest Management, 
Bureau of Forestry, Washington, D. C. 



FORESTRY COMMISSION. 51 



REPORT ON AN EXAMINATION OF THE WOODLOT OF MR. P. P. MAJOR. 
THREE RIVERS, ST. JOSEPH COUNTY, MICHIGAN. 

BY JUDSO.V F. CLARK. 

Wish of Owner. 

Mr. Major wishes to know what may be done to improve the condition of his 
woodlot. No immediate returns other than a small amount of firewood each year 
are especially required, and he is willing to go to some expense if necessary to 
put the less satisfactory portions in better producing condition. 

General. 

There is an excellent opportunity to greatly improve the present condition of 
the stand on this woodlot by the removal of the old, decrepit, and defective trees 
which are scattered almost everywhere over the area. The decay of these old trees 
offsets the growth of younger trees, and they are exceedingly injurious to those 
over which they stand. The value of the cordwood in them would leave a very 
satisfactory profit after paying the cost of the improvement cutting. 

The vigor of the stand will be greatly improved, and reproduction aided by 
the exclusion of the sheep which are grazed on the neighboring pasture, and 
which have for many, years been allowed the run of the woodlot. Reproduction 
is needed to fill the gaps in the stand and to provide a satisfactory ground cover. 

Planting must be done to fill up some of the larger gaps in the stand and to 
provide a windbreak along the western border. 

Details regarding these measures and other matters will be found below. 

Location and Area. 

This woodlot is located in Fabius township, St. Joseph county, Michigan, about 
five miles northwest of Three Rivers station, on the Lake Shore & Michigan South- 
ern, and Michigan Central Railways. 

The area is about 80 acres. 

Topography. 

The topography is quite rolling, the tract being a portion of a very irregular 
terminal moraine. The slopes vary from gentle to quite steep. The danger of 
serious erosion is such as to make the area unsuited for agricultural purposes. 

Soil. 

The soil varies in different parts from a sandy loam to a loam. It is everywhere 
deep, and on most parts contains more or less gravel. It is estimated that the 
normal annual production on the average acre does not exceed 60 cubic feet of hard- 
wood, such as oak, per acre (two-thirds of a cord of four-foot wood, or two cords 
of 16-inch stovewood). There are small areas in different parts, especially on 
the lower and more gentle slopes, where the normal annual production would 
probably reach 90 cubic feet per acre. The present average production is, how- 
ever, not more than two-thirds of what it should be. This is due to three causes: 

(1) The presence of many defective trees whose decay largely offsets new growth; 

(2) the facts that in many parts the number of trees is insufficient to fully occupy 



52 STATE OF MICHIGAN. 

the ground, and (3) the fact that in many parts the soil is greatly exposed to 
the drying winds and is unable to retain moisture sufficient for satisfactory tree- 
growth. 

The Stand. 
Its History. 

This area is a portion of a large "oak opening." The original stand, consist- 
ing of oak and hickory, was quite open, a result of very frequent fires in the early 
days before the country was settled. The stumps of these old trees show many 
fire-scars, indicating severe fires at various times. As the country became settled 
these fires ceased and gradually the open places became filled with young trees. 

When the old timber was cut by the lumbermen it would appear that a very 
large proportion of these younger trees was also destroyed. A remnant sur- 
vived, however, and they together with the sprout growth which followed the 
lumbering and the culls of the original stand which wei-e not removed at the time, 
constitute the present stand. 

Its present condition. 

The present stand consists of three distinct age-classes, viz: (1) The scatter- 
ing remnant of the original stand, consisting of old, crooked, unsound trees left 
a"' worthless by the lumbermen, (2) a sprinkling of 50 to 60-year-old trees which 
appeared with the cessation of the former fires and were not destroyed during 
the subsequent lumbering, and (3) the sprout-growth which came from the stumps 
of the younger trees cut or destroyed during lumbering. The ages of this last 
class vary from five years up according to the time of the lumbering which has 
been carried on at various times during the last 35 or 40 years. 

The species occurring are almost exclusively oaks and mockernut hickory, with 
aspen on several areas. Dogwood and sassafras are very common in the under- 
growth. White oak predominates, and red and black oak occur. Hickory forms 
8.bout one-tenth of the stand. 

The density of the stand varies greatly. In a few comparatively small areas 
it is all that could be desired; on much the greater part it is open, and in many 
places, especially on recently cut-over areas, it is very open. This is largely a 
result of the sheep-grazing which has been permitted in recent years, a satis- 
factory reproduction of timber trees being impossible under these conditions. 

It has already been stated that the rate of growth of the trees is in many parts 
quite unsatisfactory. This is caused almost wholly by the destruction of the 
undergrowth by the sheep. The absence of the normal undergrowth permits the 
wind to blow the leaves from the more exposed parts, which are the very parts 
where they are most needed. Leaves are a natural and efficient mulch for a forest 
soil; their absence permits the soil to dry out by direct evaporation. The absence 
of an undergrowth permits the sunlight to reach the soil, causing the humus to 
be unduly oxidized, and stimulating the growth of the grass on the forest floor. 
The loss of humus causes a lessened moisture-holding capacity in the soil, and 
the growth of grass means a further drain on the depleted moisture supply. Since 
moisture is by far the most important element in a forest soil — is indeed almost the 
one factor that raises or lowers the producing capacity of most forest soils — it will 
be understood how much this absence of an undergrowth means to the thrift of 
the stand. 

Treatment. 

For the purpose of prescribing treatment, the three essentially different condi- 
tions of stand will be discussed separately. 

1. Oak stand of all ages. 

This will serve to designate the stand which occupies fully 60 of the 80 acres 
and the entire southern portion of the quarter-section. Although the sprout-growth 
varies greatly in age and density of the stand, its silvicultural condition is other- 
wise the same throughout the area. 

Grazing should of course be discontinued at once in this as in the other stands. 

Improvement cuttings. — All the old defective trees should be removed. This 
cutting should be made from year to year as fuel is needed, but the sooner it is 
completed the better for the woodlot. In connection with the removal of the old 
trees, all dogwood and sassafras should be cut. Much of this is suitable for 



FORESTRY COMMISSION. 53 

fuel, and the ground should be cleared of such Inferior material to make way for 
better stock. 

Thinninos. — After the improvement cuttings have been completed, say in 10 
years, there will be many of the younger groups or portions of the stand that 
would be greatly helped by a thinning. In these thinnings, all dead and dying 
trees should be cut, and such of the remainder as are of inferior form or 
species and are injuring the crowns of better trees either by shading or by 
contact during wind storms. The openings in the crown cover caused by the 
removal of such trees should as a rule not be greater than may be reasonably 
expected to close again by growth in five to seven years. By closing is meant 
the coming together of the tips of the branches of the trees. 

Plantinci. — There are many open places in the stand, and with the removal of the 
over-mature trees there will be many more where the natural reproduction has 
been and will be less satisfactory than is desirable. As Mr. Major wishes to 
produce fence posts, and has an excellent market for pulpwood, it is recom- 
mended that in the higher and dryer portions these open places be planted to 
black locust, and that the lower and moister situations be set out to Cottonwood. 
The black locust should be set out as one-year-old plants and spaced 5x.5 or at most 
(;xt> feet where it is entirely open and should be placed between the scattering 
bunches of oak coppice where such occur. The cottonwood can best be planted 
by the use of cuttings. Eight or ten-inch pieces of the one and two-year wood 
of the branches, pointed at the lower end and inserted in the soil will be entirely 
satisfactory. They should be placed in a sloping position, with one or two buds 
above the surface, at the distances above indicated for the black locust. These 
cuttings should be prepared during the dormant season, and kept in moist sand 
until needed. 

A number of poplar occur throughout the stand, and there are two small areas 
where they form practically pure stands. The scattering poplar, which are now 
of verv satisfactory size for pulp, may be utilized for that purpose within the 
next fiVe or at most 10 years, greatly to the advantage of the other growth over 
which they stand. They are now of very satisfactory size for pulp and will in 
a few years be past their prime. The poplar groups are about 18 years old. six 
inches in dianieter. and average fully 55 feet high. They are very thrifty, and 
may be retained to advantage 10 or 15 years before cutting. 

2. The 1877 Burn. 

All voung trees on a small area towards the north end were destroyed and 
most of the larger trees scarred badly by tire in 1877. The best of the larger trees 
have since been cut, and the remainder should be cut at an early day. The area 
could then be planted to locust or white pine. Tall-growing weeds being absent, 
two-year-old untransplanted pine stock will be satisfactory if about 15 inches 
square of the sod be removed in each place before planting the pines. This sod 
should be placed around the pines in an inverted position after setting, for mulch 
purposes. The pines should be spaced five feet apart, each way. 

3. Old oak stand. 

This stand at the north end of the woodlot has been much less severely cut 
than the remainder of the area. The stand consists of red, black, and white oaks, 
with some mockernut hickory. Diameters up to 30 inches, and heights up to 70 
feet occur. The quality is poor, the better trees having been removed some years 
ago. What reproduction formerly existed was largely killed by the fire in 1877 
which ran over most of the area, but was not sufRciently severe in this part to 
scar the older trees. Grazing has prevented any reproduction in recent years. 
The ground is closely grassed over. 

Treatment. — This stand is mature, and should be removed during the next ten 
years. The first consideration is to get a reproduction of good trees to form the 
basis of the future stand. Grazing must be discontinued, and weed trees whose 
seed is not desired should be removed at onee. 

In view of the heavy sod and the open condition of the stand it is recommended 
that the sod be broken before the fall of the nuts and acorns, by rough cultiva- 
tion with a disk harrow. This should be followed after the fall of the seeds by 
dragging over with a light harrow. This will plant at a trifling expense many 
thousands of acorns and nuts per acre, and will insure a fine reproduction. 

In order to admit light for the development of the new crop, a heavy thinning 
should be made the following winter, in which all of the most inferior trees 



54 STATE OP MICHIGAN. 

should be taken. This thinning should remove about one-third of the stand. As 
soon as the young growth is thoroughly established in satisfactory density the 
old stand may be entirely harvested. The very few trees of good form which are 
in the present stand may be retained to continue their growth with the new 
stand, but this is not especially recommended since they are few in number and 
would be liable to die at the tops as a result of their standing so open as to 
favor the development of "water-sprouts." 



Protection. 

Felling. — Care should in all cases be exercised to avoid as much as possible 
injury to valuable young growth by the felling of the old trees. Stumps should be 
cut as low as practicable, and with the saw. There should be no "brushing out" 
of the young growth. 

Disposal of dehris. — As much as practicable of the branches and tops should be 
utilized for firewood. The remaining debris should either be piled and burned 
in the open places during a time when the fire will not endanger the woods by 
running; or be scattered and made to lie as close to the ground as practicable 
in order to hasten decay, and thereby lessen the danger from fire and interference 
with young growth. 

Grazing. — The importance of the exclusion of all live stock has already been 
fully discussed. 

Fire. — The keeping of the woodlot free from dangerous debris is the only meas- 
ure, other than care in the handling of fire within or near the woodlot, that is 
considered necessary for the protection of the woodlot from fire. The fact that 
but one fire of any importance has occui;red on the area since the settlement of 
the country indicates that danger from this source is not great. 

Windbreak. — It is recommended that a row of Norway spruce be planted along 
the western side of this woodlot wherever the stand is sufficiently open to admit 
of their growth. Such a row of spruce will be of great value in the future in 
shutting out the wind from the stand. The trees may be planted six or eight feet 
apart and if good stock be used a single row will be sufficient. 



No treatment of woodlots is more commonly practiced than tlie I'^moval 
of the valuable trees and the leavinji of the inferior in full possession of 
the soil, and this notwithstanding the fact that it must appear evident 
to every thoughtful person that such practice must inevitably lead ulti- 
mately to the total exclusion of the more valuable trees, and consequently 
to a marked lowering of the value of the yearly product of the woodlot. 

In the report quoted, the subject of thinnings is also touched upon. It 
might be of interest here to enlarge upon this topic which is so important 
in the management of young stands. 

All stands grown under proper conditions of density in their early years 
re(]uire to be thinned later by the removal of a number of the trees pres- 
ent, that the remaining trees may be given sufficient room in which to 
develop. A density of at least 1,500 trees per acre is desirable during the 
early years in stands of any species, and a much larger number may be 
present with advantage. It is, of course, impossible that any such num- 
ber can remain on the ground till maturity, and, if untouched by man, a 
natural thinning will take place, by means of which the original number is 
gradually reduced through the death of the trees which are overtopped by 
those making a more rapid growth. 

A thinning by the hand of man may have several great advantages over 
an unaided thinning by nature. The chief of these are: 

First. Control of the species in the stand. 

It often happens that trees of less valuable species overtop and shade to 
death trees of the more valuable species in tlie natural forest. The re- 



FORESTRY COiMMISSION. 55 

iiioval of such inferior h-eos before Ihey have seriousl}' injured their better 
neiuhboi-s is, of course, always desirable. 

>^i'c(>ti(l. Control of the (luality of the tindier i)roduced. 

It often happens that many of the dominant trees of the stand are more 
or less defective in form or in soundness. The stand will, of course, be 
iiiiprovcd by their removal before they have seriously injured better trees 
in their ijnmediate neiohborhood, which, on their removal, may be able to 
utilize the s])ace to better advantage. 

Tltird. The maturity of the crop may be hastened. 

If we assume hat a ])ine tree of thirty inches in diameter is matui-e. it is 
safe to say that the maturity of the pine stand may be hastened by at 
least twenty years by judicious thinninj^. This is accomplished by the 
opening; up of the canopy or crown cover from time to time to enable the 
trees which are to constitute the final stand to enlarge their crowns and 
thereby make possible a more rapid increase in diameter. 

Fourth. Valuable wood may be saved. 

Just how valuable this wood may be depends entirely on the location 
of the woodlot and the character of the stand. Where the stand thins 
itself without the aid of nuin, all trees which are killed by this jtrocess 
are lost by the ravages of insects and decay. On most farms this material 
might be utilized to advantage for fuel, posts, vine crops, rails and other 
purposes. 

The time at which, a first thinning should be carried out in a dense young 
stand will be very largely determined by the local market conditions. As 
a rule, no thinning should be undertaken until the material to be removed 
will have acquired sufficient size to be of value for fuel or for some other 
purpose. On most woodlots in Southern Michigan this time will usually 
come when the stand is between fifteen and twenty-five years old. It is 
true that in leaving the stand so long untouched many good trees may be 
seriously injured by being overtopped by inferior neighbors, which have 
chanced to have gotten the upper hand in the struggle for light, but as a 
rule there will still remain many more good trees unharmed than are re- 
quired for the future stand. In the case of some very rapid growing trees, 
especially where the quality of the wood makes the product merchantable 
au an early day, as in the case of Catalpa and Black Locust, the first 
thinning may be carried out to advantage as early as the sixth or seventh 
year. 

The amount of material to be removed in a thinning of this kind will 
depend on the site, the species, and the purpose for which the timber is 
grown. In general, it may be said that trees occupying situations very 
favorable for tree growth may be thinned more severely than when the 
location is less favorable. The more rapid growing species, and those 
capable of enduring greater shade, may also be more heavily thinned than 
such as grow more slowly or are incapable of enduring great shade. As 
a rule, no opening shuld be made in the crown cover which cannot reason- 
ably be expected to close again in the course of five to seven years. 

It should be added in this connection that the margins of woodlot should 
not be as heavily thinned in any case as the interior, unless they are 
thoroughly protected by a windbreak mantle. This is particularly true 
of western borders. 

The overcutting ofthe mature timber in Avoodlots is not of infrequent 
occurrence. A number of woodlots were noted where the owners, think- 



56 STATE OB" MICHIGAN. 

ing to improve the stand, had very carefuHy cut out the inferior and de- 
fective trees, but to such an extent that the remaining stand was left in 
a very unfavorable condition for development. 

The opening of the stand too freely checks the growth of the trees by 
making the conditions less favorable for the retention of moisture, and 
has, with many trees, the additional danger of checking their height 
growth by permitting the development of the base of the crown, and in 
some trees (e. g. Oaks) by the development of water sprouts on their 
trunks. In many cases such tliiunings as those result in the ultimate 
death of the top of the tree. This, of course, occurs during some excep- 
tionally dry time, and the weather conditions are usually blamed for it. 
The loss of soil moisture as a result of overcutting is due to the increased 
air motion at the soil surface and the admission of sufficient light to 
stimulate the growth of grass and other moisture-robbing weeds on the 
forest floor. The excessive light (and heat) increases the oxidation of 
the organic matter in the soil, thereby lowering its moisture-holding ca- 
pacity, and raises the temperature, thereby increasing the direct evapo- 
ration of moisture. 

If the trees of the stand are sufficiently matured to produce seed abun- 
dantly, such an overcutting will result in a natural reproduction of for- 
est trees. Should the stand be nearly mature, this would be a desirable 
condition, but in all immature stands the harm done by the overcutting 
is but \er\ slowly repaired by nature. 

That overcutting in a woodlot open to the run of live stock should be 
more serious where grazing is practiced than otherwise can be readily 
appreciated. In the former case the absence of an undergrowth will 
leave the soil wholly unprotected, and there will be no young trees to 
develop to fill the gaps in the stand. 

A detailed discussion of the injuries due to grazing, fire, insects, and 
other causes of injury common to Michigan woodlands would unduly 
lengthen an article already too long, and must be deferred for the present. 
Suffice to say, it is the intention of the bureau to publish at an early day 
a somewhat extended account of a study of woodlot conditions in South- 
ern Michigan, which will be available for general distribution. 



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